Hybrid beamforming in uplink massive MIMO systems in the presence of blockers
Paper i proceeding, 2017

Hybrid beamforming (HBF) is a potential solution to reduce the baseband hardware cost in massive multiple-input multiple-output (MIMO) systems that has drawn considerable attention recently. In this paper, we consider the uplink of a multiuser massive MIMO system in the presence of blockers. Such blockers, which arise from, for example, users served by other non-cooperative base stations (BSs), can limit the system performance if not handled properly. We propose a HBF scheme that can remove the impact of blockers, while preserving signals from intended users. Specifically, in our two-step receive beamforming scheme, the analog beamformer (ABF) is designed based on channel covariance matrices to minimize the powers of blockers, while the digital beamformer (DBF) deals with inter-user interference. We propose an iterative algorithm that efficiently gives a good sub-optimal solution to the NP-hard problem in the ABF design. Moreover, we consider a more complete BS architecture by incorporating automatic gain control (AGC) and analog-to-digital converter (ADC). As we show in the simulations, for a system with full-precision ADCs, our scheme approaches the sum rate of an ideal fully-digital system. Interestingly, for a system with low-resolution ADCs, our HBF scheme can even outperform a fully-digital system.


Xinlin Zhang

Signaler och system, Signalbehandling och medicinsk teknik, Signalbehandling

Mikael Coldrey

Ericsson Sweden

Chalmers University of Technology

Thomas Eriksson

Signaler och system, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

Mats Viberg

Signaler och system, Signalbehandling och medicinsk teknik, Signalbehandling

ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings

15206149 (ISSN)

6503-6507 7953409


Informations- och kommunikationsteknik